Commit message: Add more validation to `RequantizationRangePerChannel`.

PiperOrigin-RevId: 387693946
Change-Id: Ife8dcbdb021bec4787eef6a4361dd08f17c14bd6
CVE: CVE-2021-37665
CWE: CWE-703
Vulnerability description: TensorFlow is an end-to-end open source platform for machine learning. In affected versions due to incomplete validation in MKL implementation of requantization, an attacker can trigger undefined behavior via binding a reference to a null pointer or can access data outside the bounds of heap allocated arrays. The [implementation](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/core/kernels/mkl/mkl_requantization_range_per_channel_op.cc) does not validate the dimensions of the `input` tensor. A similar issue occurs in `MklRequantizePerChannelOp`. The [implementation](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/core/kernels/mkl/mkl_requantize_per_channel_op.cc) does not perform full validation for all the input arguments. We have patched the issue in GitHub commit 9e62869465573cb2d9b5053f1fa02a81fce21d69 and in the Github commit 203214568f5bc237603dbab6e1fd389f1572f5c9. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.

Project: tensorflow
File: mkl_requantization_range_per_channel_op.cc

  void Compute(OpKernelContext* ctx) override {
    const Tensor& input = ctx->input(kInputTensorIndex);
    const Tensor& input_min = ctx->input(kInputMinIndex);
    const Tensor& input_max = ctx->input(kInputMaxIndex);

    const size_t depth = input_max.NumElements();
    OP_REQUIRES(
        ctx, input_min.dim_size(0) == depth,
        errors::InvalidArgument("input_min has incorrect size, expected ",
                                depth, " was ", input_min.dim_size(0)));
    OP_REQUIRES(
        ctx, input_max.dim_size(0) == depth,
        errors::InvalidArgument("input_max has incorrect size, expected ",
                                depth, " was ", input_max.dim_size(0)));

    const float* input_min_data = input_min.flat<float>().data();
    const float* input_max_data = input_max.flat<float>().data();
    std::vector<float> ranges(depth);
    bool is_non_negative = true;
    Eigen::array<int, 2> shuffling({1, 0});
    auto input_matrix = input.flat_inner_dims<qint32>();

    // TODO: verify performance of not transposing and finding the min max
    // directly from input_matrix vs the one presented below of transposing and
    // using the transposed matrix as the transposing operation in itself might
    // be more costly.
    // Note that this operation is a calibration step for quantization and will
    // cease to exist in the final inference graph(will exist as a const node).
    auto transposed_input = input_matrix.shuffle(shuffling);

    // Find the ranges of each channel in parallel.
    float out_min_max = std::numeric_limits<float>::min();

#ifdef ENABLE_ONEDNN_OPENMP
#ifdef _MSC_VER
#pragma omp parallel for
#else
#pragma omp parallel for reduction(max : out_min_max)
#endif
#endif  // ENABLE_ONEDNN_OPENMP
    // TODO: Add eigen parallel_for
    for (int64_t i = 0; i < depth; ++i) {
      Eigen::Tensor<qint32, 0, Eigen::RowMajor> min =
          transposed_input.chip<0>(i).minimum();
      Eigen::Tensor<qint32, 0, Eigen::RowMajor> max =
          transposed_input.chip<0>(i).maximum();
      const int32_t min_per_channel = min();
      const int32_t max_per_channel = max();
      const int32_t abs_max =
          std::max(std::abs(min_per_channel), std::abs(max_per_channel));
      float scale =
          std::max(std::abs(input_min_data[i]), std::abs(input_max_data[i]));
      ranges[i] =
          scale * static_cast<float>(abs_max) / static_cast<float>(1L << 31);
      if (min_per_channel < 0) is_non_negative = false;

      // Thread-local out_min_max.
      out_min_max = std::max(out_min_max, ranges[i]);
    }

    // All local out_min_max gets max-reduced into one global out_min_max at
    // the end of the loop by specifying reduction(max:out_min_max) along with
    // omp parallel for.

    // Fixing max to clip_value_max_ (example 6.0 to support relu6)
    if (out_min_max > clip_value_max_) out_min_max = clip_value_max_;

    Tensor* output_min = nullptr;
    Tensor* output_max = nullptr;
    OP_REQUIRES_OK(ctx, ctx->allocate_output(kOutputMinIndex, {}, &output_min));
    OP_REQUIRES_OK(ctx, ctx->allocate_output(kOutputMaxIndex, {}, &output_max));
    output_min->flat<float>()(0) = is_non_negative ? 0.0f : -out_min_max;
    output_max->flat<float>()(0) = out_min_max;
  }